I’m just back from a briefing we organised in London.  The audience got to hear the details behind this story.  We’ve had a bit of a blog-fest on this topic today so you can read more by visiting Mark Avery’s blog and our News blog.

The pursuit of tidal power by the construction of massive barrages has occupied a lot of work by the RSPB over the last 30 years – for four years I was deeply involved in the process of scrutinising the potential for a Mersey barrage in the early 1990s. Today we learned a lot about the potential environmental impacts and massive ongoing costs generated by building a storm surge barrier across the Oosterscheldte in Holland (and here’s a map to show you it’s location).

The Dutch had few options given the hard-learned lessons of the devastating coastal floods of 1953.  As a storm surge barrier – it has been successful but at a cost.  A cost that is being measured in coastal erosion, increased flood risk (though not from storms) and environmental damage.  The barrier has created a sand hunger as the river and it’s estuary fight to achieve a new equilibrium.

And this is the lesson for the UK – this will be the consequence of barraging the Severn (and beyond that the Mersey, Solway, Wash and Thames) - the ravenous sand hunger will be the same.  These are impacts and costs we can avoid – we have the choice.

The search for sustainable tidal energy has been deeply skewed by the focus on the big-kit barrages that are at the most devastating end of the spectrum of impacts on our natural environment.  The lessons from the Dutch experience have been known to Government for a couple of years – and we urge the Government to publish the critically important, and delayed, studies into the impact on the tides and sediments of the Severn barrage.